My 80 07K quattro project

[Ethan Bailey]

Been on here for a couple of years searching and finding info for my 80 quattro 07K conversion and thought I'd finally put my 2 pence in and post what I've found and done so far with my 80!


started life as a 2.0 8v FWD, bought it back in 2020 as a gap car between 2 others but ended up loving it and stuck with it instead
initial plan was to 2.0 16v ABF turbo swap it so bought and fully rebuilt an ABF but that plan went completely out the window when I found out about the 07K and now the ABF is sitting in my garage looking for a new home ?

So the 07K, a modern 2.5 5 cyl in the same family as the RS3 and TTRS, in particular the one I've got an N/A CBTA. Now in the UK we never got the 07K in an n/a version only got them in ttrs/rs3 which are obviously turbo and way out of budget of what I was planning to spend. I found out that the n/a 07k came in alot of VW's in America and somewhere else I can't remember, found a company in the UK (JAAATT Engineering) that listed some parts for these on they're website, got in contact with junior and he sourced and imported me an engine in pretty quick turnaround!

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so some early versions of these come with a forged crank from factory and some don't, i got one from a 2012 jetta so mine being too new to have a forged crank but this one having 43k miles seemed like a better option and being a bit newer has the revised timing chains and a couple other bits.
got an ecu and loom from jaaatt engineering too and got the ecu de immobilised, de restricted and rev limiter raised by someone on facebook (can link if needed cant remember name rn)

Continued...

[Ethan Bailey]

So regarding the quattro swap part of things.
May 2022 i bought a B5 S4 manual estate in pretty sorry shape if I must say but all the running gear was there, engine had been removed and then just plonked back in the engine bay not bolted to anything


The s4 also had the 01E 1 - 2 shift collar issue, for those who don't know the gears to select 1st and 2nd lock together so makes the gearbox unusable basically, JHM motorsport do a full rebuild kit to remove this issue and then comes with a full set of carbon synchros too, so with the help of a friend we stripped the gearbox completely installed all new parts, painted a few bits of the casing and got it back together over a weekend... fun
After rebuilding the gearbox we got the s4 back into a drivable state which took a while of head scratching considering we didnt take it apart, just to test the gearbox which worked perfectly, then stripped it all back down again *sigh*

The 80 then underwent the complete strip down top to bottom front to back, everything out that could possibly come out other than interior loom. not going to go into detail on that as thats the boring stuff lol

So, the quattro bits
The floor pan of saloon and avant 80 and S4/A4 avant and saloon are almost identical as far as I'm aware.
audi 80's pre 1993 have the rear subframe mount nuts in them already, mine being a 1994 did not. However after being told it can't be done by a few people on Facebook and my stubborn a** being the way I am I had to prove them wrong lol, s4 rear subframe mount is, surprise surprise, the same. We cut out a big section of the chassis rail from the s4 both sides and took to the 80 to compare, stripped the outer chassis rail off the captive nuts and strengthening plates and made them fit into the 80 chassis rail, welded them in and closed them up. Front diff mount is slightly different on the s4 at the tunnel and just needed some shaving down to fit snug but after the little bit of trimming it slotted in like a puzzle piece.
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oh and yes the 80 was on a rotisserie while doing all this

continued when i get a chance next

[tango123]

Interesting project. Does anyone make the engine mounts to fit the 07K into b4 or you will fabricate some?

[Tractor Dave]

Yes agree. Very interesting project. Keep it coming.

[david1980]

there are a few people who make the mounts.

I paid $100 for my 07k with forged crank off a person in NY state, just need to ship it. They are a cheap buy. Its the parts to use it that cost a fortune like the sump.

[Tractor Dave]

So what power does a naturally aspirated 07k make?

[Ethan Bailey]

Interesting project. Does anyone make the engine mounts to fit the 07K into b4 or you will fabricate some?

I believe there's a couple people that make mounts out there but I'm currently making my own to try and save a bit of money where I can lol

[Ethan Bailey]

So what power does a naturally aspirated 07k make?

In the region of 150 - 170 so nothing to shout about but they do take boost quite well, a few people I've seen run 7-9 psi and make just shy of 300 bhp, if running forged internals then they cam surpass 1000bhp quite easily from what I've seen

[Ethan Bailey]

there are a few people who make the mounts.

I paid $100 for my 07k with forged crank off a person in NY state, just need to ship it. They are a cheap buy. Its the parts to use it that cost a fortune like the sump.

It's the shipping that's a killer to get one the UK but still works out alot cheaper than an rs3/ttrs engine over here
I've cut and made my subframe around the sump instead of getting a different sump to fit the original subframe, some of the other bits were a bit pricey but are good quality parts to be fair

[rxl]

nice project. cant wait to see iton the road

[psiconauta911]

[Ethan Bailey]

Next thing on the agenda was center propshaft bearing, removing the old gearbox mount and some clearance for the shifter linkages as I'm using the S4 setup, I know there's a way of cutting and welding the 80 linkage on but this seemed easyer as it was on the rotisserie anyway

Propshaft bearing mounts were cut off the S4, had to make some little spacers as the tunnel is a bit wider on the 80 it seems but all welded in fine

The clearance for the shifter linkages

for anyone doing this if anyone at all then my advice would be to take a bit more off where the studs are for that clearance as I'm at the point now the gearbox is in and its very tight, going to try and give it a clout to get a tad more clearance but too far ahead to start cutting and welding again, I'll take some photos of what I mean when I get a chance next
old gearbox mount cut off, took a bit more metal than intended but welded them back up and closed the holes up after

one thing we did which I'm still unsure if ittl even work but thought I'd take the chance is fitting the S4 handbrake, the 80s handbrake felt pretty naf and could never seem to get any decent bite on it, not only that with the total of about 6 teeth on it, it was just not very nice to use lol, cut the complete tunnel out of the S4 at this point to see what I needed, cut out the mount and some of the tunnel with it, cut the 80 one out and welded the S4 one in with alot of trial and error fitting the center console to make sure it lined up perfect
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only photos I have to hand at the moment, can get some more and go into a bit more detail if anyones interested

Had a small little rust repair in the rear drives side arch, self explanatory
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Next thing we did was cut out the battery tray as thatll be going in the boot

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Continued

[K Simmonds]

What an interesting project, it's quie an undertakeing to convert a FWD B4 to 4WD though perfectly fesiable.

We had an FWD B4 Saloon on the ramp at work to size it up and it's a lot of work altogether. Having a complete doner car like your B5 S4 is pretty much essencial as so many bits are required, I guess one could purchase all the parts seperatly but that would be a PITA and almost certainly more expensive.

I see you've deleated the battery tray from the engine bay to move it to boot which is a good move, in the pic there's no sign of the ABS unit that normally sits in front of it on four/five cylinder B3 cars. Have you done away with that as well or is located else where on a B4 four pot, I have had a look but remember?

Not many people use the 07K engine as it doesn't just bolt in, extensive modifcations are required to get the sump to clear the subframe though you've done a great job of that.

Then one either has to purchase or fabricate engine mounts.

Are you going to use a stock ECU or go aftermarket?

Anyway this is a cool idea even if it is a great deal of work, makes the G60 conversion I'm doing on my B3 look like childs play!

[Ethan Bailey]

What an interesting project, it's quie an undertakeing to convert a FWD B4 to 4WD though perfectly fesiable.

We had an FWD B4 Saloon on the ramp at work to size it up and it's a lot of work altogether. Having a complete doner car like your B5 S4 is pretty much essencial as so many bits are required, I guess one could purchase all the parts seperatly but that would be a PITA and almost certainly more expensive.

I see you've deleated the battery tray from the engine bay to move it to boot which is a good move, in the pic there's no sign of the ABS unit that normally sits in front of it on four/five cylinder B3 cars. Have you done away with that as well or is located else where on a B4 four pot, I have had a look but remember?

Not many people use the 07K engine as it doesn't just bolt in, extensive modifcations are required to get the sump to clear the subframe though you've done a great job of that.

Then one either has to purchase or fabricate engine mounts.

Are you going to use a stock ECU or go aftermarket?

Anyway this is a cool idea even if it is a great deal of work, makes the G60 conversion I'm doing on my B3 look like childs play!

Yeah it's been quite the project so far but it is do able with just the parts however just seemed easyer to buy the S4 and then sell the parts I didn't need to recoup some money

i forgot to mention the abs, but yes I've done away with it, it is mounted in the same place normally but I've got a willwood brake bias instead in its place

modifying the subframe seemed like the easyer option and was relatively easy to do, and I'm currently making the engine mounts as it's easy enough to do just setting up the angle of of the engine to clear the bonnet lol

As for the ecu I'm using the stock 07k ecu for now as im only running it N/A to begin with anyway, I had the ecu de immobilised, de limited, rev limiter increased, and a few other bits changed to be able to run independently

[Ethan Bailey]

These are the photos of where I was saying about clearance for the gearbox and the shift linkages
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Right. Fuel tank
so I didn't want to try and find a quattro fuel tank, yes it probably wouldve been easyer and wouldve saved time but i had the s4 fuel tank and it didn't really take that long to cut and fit it in, the fuel filler neck is wider from the s4 so I cut out then inside of the arch, the filler point also sits differently in the s4 too, so had the heat up the base with a couple heat guns and bend it slightly to go where the 80 fuel flap is
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We had some sheet metal and spent a bit of time getting a basic shape, tacked and welded it in to widen it.
i know the welds arent the best but im not really fussed, if it starts to rust in the future then ill cut it out and replace it again, not structural and gettimg in there was a pain lol
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After that was done the fuel tank strap mounts didnt have the nuts in them but the holes were there so just put some riv nuts in, had to weld 2 other brackets for the straps too
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Bolted in sweet after

In the process of welding somewhere along the line managed to smash one of my rear quarter windows
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If anyones got one spare i need it lol